Manufacture of dust-caps for tire-valves and the like.



PATENTED APR. 30, 1907 M. C. SCHWEINERT & H. P. KRAFT. MANUFACTURE OF DUST CAPS FOR TIRE VALVES AND THE LIKE.

.APPLIUATION FILED FEB.3.1905.

FIG. 2.

FIG.

INVENTORS:

tomeys A WQ \VZZIIJJESSES: fl M.

To whom it may concern.

" Be it known that we, MAXIMILIAN OHARLns caps and the SonwnmERr, residing at West Hoboken, in

the county of Hudson and State of New id ersey, and HENRY i; KRAr T, residing in the borough of Brooklyn, county of Kings, city and State of New X ork, citizens ofthe United States, have invented certain new-and useful iprovements in the Manufacture of Dust the following is a speeification. Y These dust caps are tubesclos'ed end designed to inclose theentire Valve, including the ordinary valve capjand arranged :5 to screw on anexternal vthreadextending throughout substantially the greater portion -The ;dust' cap, thereor the valve casing H fore, in order to accommodate the valve, should have a very long screw thread, as

,ze long as or slightly longer than theexpos'ed or {projecting portion of thevalve-fand a bor'd portion of slightly less diameterg-beyond said screwthread; or if provided'with a short sorewthread near its mouthfit must 2 5 have a diameter'fbeyond .the vscrewthread great enough to accommodate easily the larger portion of the valve. I r

Caps for the purpose stated have previously been made from a solidrod, either 3 cutting the internal screwthread throughout nearly the full length of the cap and forming a slightly smaller bore beyond; or by cutting a sorewthread only near the mouth of the captand counterboring the portion beyond the thread suiiiciently to accommodate the largest portion of the valve. Each of these processes involved considerable labor and i expense totake out all the solid coreof the rod, especially with tools for cutting screw- 4 threads, it being well understood that such toolswork more easily in cutting a thread Withina hollow pipe than into a solid rod. The old processes were also slow, and used a considerable quantity of metal for each cap.

. 5 According to our improvement the cap is made very quickly by a succession of drawing. and compressing operations, and a very 'easy' thread cutting operation on the inside of a tube. By this operation the cap can-be 5 made more quickly,

metal, and of a more ornamental appearance i CHARLES SOHWEINERT, or WEST,

AND nanny P. KRAFT, OF'NEW MANUFACTURE o lbusT-c aps FORTIRE Specification of Letters Patent. I Application filed February 3, 1905.

: at one.

.ing to the invention.

end of the bpdy portion A.

HOBOKEN, NEW JERSEY,

YORK, 'N. Y.

-VALVE S AND TH LIKE.

Patented April 30, 19( )7. J Saria1No,244,062. l I

The accompanying drawings illustrate process of making them accord- Figure 1 is an elevation of a cap; Fig. 2 shows a cap in Section, the position of the Valve being indicated in dotted lines; Figs.

3 to 7 inclusive illustrate the successive steps Figs. 8 and 9 illustrate of forming the cap. avariation in one of the ste s.

I F -Referring to the embodnnent illustrated, the tubular body Ais' slightly greater in diameter andlonger than a portion of the valve B which hes therein. C forms the portion of the cap at the lower ring in the-process offorniation may be slightly enlarged in its lateral diameter.

A knurled ring The knurled -The mouth D of the cap is of smaller diam eter than the knurled portion, and prefen' ably also than the body portion A. The

contracted mouth D is internally screwthreaded as at E,.

the screwthread termi- .nating at the point where the enlarged diameter of the knurled ring begins. Asharp-edged rib F surrounds the mouth making a broad flat bearing end or washer surface for the the knurled ring mental appearance of the cap.

111 the manufacture of a cap',-.a tube of brass or other suitable metal is' drawnin the form shown in Fig. 3, of a uniform diameter equal to' the desired diameter of the body portionA of thefinished cap. Then a por:

tion of the tube is embraced between a pair of rotating rolls G and H, the outer one of which has such a configuration as to form the knurling. This annular rolling action at the same time stretches the metal somewhat, and forms the tube of slightly larger diameter at this point. The portion of the tube between the knurled ring C and the end is then con of a much less weight of thread cu ting tool has to remove only a small quantity of metal. The portion D is cap, and with the contracted portion D of C contributing to the orna' than by the old processes. Certain other contracted to such an extent that the thread shall be perfect, with as little excess of material to be cut away as is practicable. The

Q I samsi enlarged diameter beyond the screwthread, made by those skilled in the art, without de and especially immediately beyond it within l parture from the invention. i the knurled ring C, facilitates the action of l What wool-aim 2 the thread cutting tool. It willbe seen l The process of forming a cap for tire valves therefore that practically all the metal used and the like designed to inclose an externally 30 goes into the making of the cap. There is no 5 threaded valve casing, and having a tubular Waste of -rnetal, and there is no waste of l body portion, an enlarged knurledri'ng at the power and time in cutting away a quantity l end of said body portion, and a screwthread-; of metal. The work of the several tools is ed end of smaller diameter than said body to very light, and the product is of graceful i portion which consists in drawing a tubular- 5 shape and may be made very light. body of metal of a uniform diameter greater The contracted portion D of the screw 1 than that of the threaded casing, enlarging-a threads may be formed in one operation. 1 portion of said body intermediate itsends by For example Figs. 8 and 9 show an inner annular rolling and simultaneously knurling 15 mandrel K fitting in the mouth of the tube the same by the configuration of the outer 40 and upon which the metal is contracted by I roll. v means of outer dies L; the faces of the manl In witness whereof, we have hereunto l l l l l drel and dies being threaded so as to contract signed our names in the presence'of two subthe tube on the mandrel and to form the scribing witnesses. 2o screw-threads at the same time. r v 1 Though we have described with great par- I figit g fgi ticularity of detail a certain specific process, L yet it is not to be understood that the invenl W'1tnesses':

tion is limited to the specific embodiments DOMINGO ,A. USINA, 2 5 disclosed. Various modifications may be THEODORE T. SNELL. 

